Rail coupling

ABSTRACT

A releasable rail coupling (1000) for releasably coupling a first rail 10A providing a first portion P1 of a miming surface RS for a wheel (120) and a second rail (10B) providing a second portion P2 of the miming surface RS is described. The rail coupling (1000) comprises a first part (1100) having a first end 1110 comprising a first male coupling member (1111) and a second end (1120) arranged for joining to the first rail (10A). The rail coupling (1000) comprises a second part (1200) having a first end (1210) comprising a corresponding first female coupling member (1212), arranged to receive the first male coupling member (1111) therein, and a second end (1220) arranged for joining to the second rail (10B). The rail coupling (1000) is arrangeable in a first configuration wherein the first male coupling member (1111) and the first female coupling member (1212) are uncoupled. The rail coupling (1000) is arrangeable a second configuration wherein the first male coupling member (1111) and the first female coupling member (1212) are coupled by receiving the first male coupling member (1111) in the first female coupling member (1212). The rail coupling (1000) provides a third portion P3 of the running surface RS in the second configuration. In this way, assembly and/or disassembly of the first rail (10A) (i.e. a first length of rail) and the second rail (10B) (i.e. a second length of rail) may be facilitated and/or errors in assembly reduced.

FIELD

The present invention relates to rail couplings for releasably couplingrails and to rail assemblies including rails and such rail couplings.

BACKGROUND TO THE INVENTION

Typically, a zipline (also known as a zip-line, zip wire, aerial runwayor aerial ropeslide) comprises an inclined cable, secured only at upperand lower ends thereof, and a trolley (also known as a bogey), includinga freely-rolling pulley. A user (i.e. a load), suspended from thetrolley, may be accelerated by gravity from the upper end to the lowerend of the inclined cable. In use, the pulley rolls along an uppermostportion of the inclined cable. A gradient of the inclined cable istypically in a range from 1 in 20 to 1 in 30. Usually, the inclinedcable sags and appropriate tensioning of the inclined cable is requiredto control acceleration of the user. Since the inclined cable is securedonly at the upper and the lower ends thereof, the inclined cable isrestricted to a linear path, without lateral deviations, such as curvesor bends.

To provide a non-linear path including lateral deviations, such ascurves or bends, the cable may be replaced with a rail, typically amonorail. The non-linear path enables the rail to curve aroundobstacles, for example, and/or to increase user enjoyment. An uppermostportion of the rail may be fixed to a framework or hung from ceilingjoists or trees, for example, such that a region under the rail remainsunobstructed for the trolley and the user to travel through. That is,the rail is a suspended rail, situated at a height typically in a rangefrom 2 m to 10 m, above the ground. A typical rail includes a tubehaving an axial (also known as longitudinal) flange, for fixing orhanging, upstanding therefrom. The pulley is replaced by one or morefreely-rolling wheels, that roll along the rail on an upper lateralportion or portions thereof, clear of the fixed uppermost portion. Forexample, the wheels may roll either side of the axial flange. Forsafety, the trolley is arranged to be captive on the rail, such that thetrolley (i.e. a captive trolley) remains on the rail, in use. Two ormore trolleys may be captive on the rail, such that two or morerespective users may travel thereon. The rail is generally inclined,having a mean gradient typically in a range from 1 in 10 to 1 in 60,though may include one or more descending portions, ascending portionsand/or horizontal portions. A total length of the rail may be in excessof 500 m, including multiple curves or bends, descending portions,ascending portions and/or horizontal portions. An installed rail may beknown as a rail track. The rail may be a continuous (also known as anendless) rail, forming a closed rail track.

Typically, the rail is provided in lengths (also known as sections), forassembly on site. The assembly of the rail typically includes fittingand joining of adjacent lengths, typically by welding. Fitting and/orjoining may be complex due, at least in part, to the rail includingmultiple curves or bends, descending portions, ascending portions and/orhorizontal portions. Errors in the assembly, for example faults and/ordiscontinuities may increase loadings on, and/or rates of wear of, thetrolley and/or rail. These errors may adversely affect rail integrity,trolley reliability and/or user safety, for example. Faults, such ascracks, lack of welding penetration, slag lines or undercut, maycompromise structural integrity of the rail. Discontinuities, such assteps or gaps between the adjacent lengths, may increase loading and/orvibration and hence wear and/or fatigue. The assembly of the rail may beperformed in situ (i.e. at height), since obstructions such aspre-existing structures or trees may prevent assembly of the rail on theground before subsequent lifting to the height, complicating assembly.Hence, errors may be more prevalent and/or exacerbated for in situassembly. Furthermore, disassembly of the rail, for example to replace adamaged length or to resite the rail, may be problematic, for examplerequiring in situ cutting and subsequent refitting and rejoining of therail.

Hence, there is a need to improve joining of rails, for example toimprove rail integrity, trolley reliability and/or user safety.

SUMMARY OF THE INVENTION

It is one aim of the present invention, amongst others, to provide areleasable rail coupling, a rail section comprising a part of a railcoupling, a method of manufacturing a rail section, a rail assembly anda kit of parts for a rail assembly including a set of rail sections anda method of assembling a rail assembly which at least partially obviatesor mitigates at least some of the disadvantages of the prior art,whether identified herein or elsewhere. In this way, rail integrity,trolley reliability and/or user safety may be improved.

A first aspect provides a releasable rail coupling for releasablycoupling a first rail providing a first portion of a running surface fora wheel and a second rail providing a second portion of the runningsurface, the rail coupling comprising:

a first part having a first end comprising a first male coupling memberand a second end arranged for joining to the first rail; and

a second part having a first end comprising a corresponding first femalecoupling member, arranged to receive the first male coupling membertherein, and a second end arranged for joining to the second rail;

wherein the rail coupling is arrangeable in:

a first configuration wherein the first male coupling member and thefirst female coupling member are uncoupled; and

a second configuration wherein the first male coupling member and thefirst female coupling member are coupled by receiving the first malecoupling member in the first female coupling member;

wherein the rail coupling provides a third portion of the runningsurface in the second configuration.

A second aspect provides a rail section providing a portion of a runningsurface for a wheel, the rail section comprising a rail and a first partand/or a second part of a rail coupling, according to the first aspect,joined thereto.

A third aspect provides a method of manufacturing a rail sectionaccording to the second aspect, the method comprising:

joining, by welding, the first part and/or the second part of the railcoupling member to the rail; and optionally, machining the weld.

A fourth aspect provides a rail assembly, or a kit of parts for a railassembly, comprising a set of rail sections, including a first railsection and a second rail section, according to the second aspect.

A fifth aspect provides a method of assembling a rail assembly accordingto the fourth aspect, comprising:

moving the rail coupling from the first configuration to the secondconfiguration.

DETAILED DESCRIPTION OF THE INVENTION

According to the present invention there is provided a rail coupling, asset forth in the appended claims. Also provided are a rail sectioncomprising a part of a rail coupling, a method of manufacturing a railsection, a rail assembly and a kit of parts for a rail assemblyincluding a set of rail sections and a method of assembling a railassembly. Other features of the invention will be apparent from thedependent claims, and the description that follows.

Rail Coupling

The first aspect provides a releasable rail coupling for releasablycoupling a first rail providing a first portion of a running surface fora wheel and a second rail providing a second portion of the runningsurface, the rail coupling comprising:

a first part having a first end comprising a first male coupling memberand a second end arranged for joining to the first rail; and

a second part having a first end comprising a corresponding first femalecoupling member, arranged to receive the first male coupling membertherein, and a second end arranged for joining to the second rail;

wherein the rail coupling is arrangeable in:

a first configuration wherein the first male coupling member and thefirst female coupling member are uncoupled; and

a second configuration wherein the first male coupling member and thefirst female coupling member are coupled by receiving the first malecoupling member in the first female coupling member;

wherein the rail coupling provides a third portion of the runningsurface in the second configuration.

In this way, assembly and/or disassembly of the first rail (i.e. a firstlength of rail) and the second rail (i.e. a second length of rail) maybe facilitated and/or errors in assembly reduced.

Particularly, the rail coupling is a releasable rail coupling, therebysubstantially reducing effort and/or force required for coupling thefirst rail and the second rail, for example during assembly on site.Hence, the assembly of a rail may be provided by coupling such railcouplings provided between successive lengths of rail, for example onsite, including in situ. That is, conventional fitting and/or weldingmay be avoided and/or eliminated. Furthermore, the disassembly of therail, for example to replace a damaged length or to resite the rail, isimproved, for example without requiring in situ cutting and subsequentrefitting and rejoining of the rail. In addition, the rail couplingmaintains and/or enhances user safety since structural integrity may bemaintained, even during significant deformation, as described below inmore detail. Furthermore, grub screw retention of the rail coupling onthe first rail and/or the second rail, for example, is not required,facilitating assembly and disassembly while also eliminating amaintenance requirement arising from such grub screws. For example, grubscrews may vibrate loose in use, compromising safety and hence requiringfrequent maintenance to check and/or re-tighten.

Particularly, since coupling of the rail coupling is effected bycoupling the first male coupling member and the first female couplingmember, errors in the assembly may be reduced. As described above,errors such as faults and/or discontinuities may increase loadings on,and/or rates of wear of, a trolley and/or rail. These errors mayadversely affect rail integrity, trolley reliability and/or user safety,for example. Faults, such as cracks, lack of welding penetration, slaglines or undercut, may compromise structural integrity of the rail.Discontinuities, such as steps or gaps between the adjacent lengths, mayincrease loading and/or vibration and hence wear and/or fatigue. Theassembly of the rail may be performed in situ (i.e. at height), sinceobstructions such as pre-existing structures or trees may preventassembly of the rail on the ground before subsequent lifting to theheight, complicating assembly. Hence, errors may be more prevalentand/or exacerbated for conventional in situ assembly. In contrast, bycoupling the first male coupling member and the first female couplingmember, such faults are avoided and/or eliminated since conventionjoining by welding mat not be required while discontinuities may becontrolled, for example to within predetermined tolerances. In this way,rail integrity, trolley reliability and/or user safety may be improved.

The releasable rail coupling is for releasably coupling a first railproviding a first portion of a running surface for a wheel and a secondrail providing a second portion of the running surface.

It should be understood that the rail coupling is a releasable railcoupling, which may be coupled and uncoupled, for example repeatedly.That is, the first rail and the second rail may be mutually attached andsubsequently detached using the rail coupling.

It should be understood that the rail coupling is for releasablycoupling the first rail and the second rail. That is, the rail couplingforms a part of a rail assembly, provided by coupling the first rail andthe second rail via the rail coupling, and hence contributes to astructural integrity of the rail assembly. In use, the rail assembly maybe subject to forces, for example due a weight thereof, residualstresses therein, fixing thereof as described above, a trolley runningthereon and/or a load, for example a user, suspended therefrom. That is,the rail coupling is for structurally, for example rigidly c.f.flexibly, and releasably coupling the first rail and the second rail.Particularly, the first male coupling member and the first femalecoupling member, arranged in the second configuration, effectivelytransfer the forces between the first rail and the second rail.

Typically, the load comprises and/or is a user, having a mass in a rangefrom 30 kg to 120 kg and hence a weight in a range from 294 N to 1,177N. In addition, centripetal forces due to cornering may add up to 1.5 ghorizontally (i.e. up to 441 N to 1,766 N). Furthermore, an increasedvertical load due to down swing (for example, the user swinging from anincline to a vertical position) may add up to 0.6 g vertically (i.e. upto i.e. up to 176 N to 706 N) with no horizontal component. The user maybe attached to the attachment member via a harness (also known as asuspension harness), for example. The harness may be include a dorsalD-ring, for example, for attaching to the attachment member via a slingor lanyard. In this way, in use, the user may be suspended in a hangglider-type (also known as a superman) position (i.e. prone or facedown). The trolley may include a handle, for the user to hold when insuch a prone or face-down position.

It should be understood that, in use, the load results in (i.e. givesrise to) a downwards vertical force due to gravity, which may beimposed, at least in part, on the rail via the trolley. The load mayresult in (i.e. give rise to) other forces, for example due to pitching,yawing and/or rolling of the load and/or due to centripetal forces onthe load, as described below, that maybe imposed on the trolley and/oron the rail via the trolley. It should be understood that the rail isgenerally inclined, having a mean gradient typically in a range from 1in 10 to 1 in 60, though may include one or more descending portions,ascending portions and/or horizontal portions. For example, a rail mayinclude an initial length having a mean gradient of about 1 in 13 (toaccelerate the trolley initially), followed by an intermediate lengthhaving a mean gradient of about 1 in 25 (corresponding approximatelywith constant speed of the trolley) and a final length having a meangradient of about 1 in 50 (to decelerate the trolley).

It should be understood that the first rail provides the first portionof the running surface for the wheel, for example of a trolley, and thesecond rail provides the second portion of the running surface. That is,the running surface is a surface for the wheel to run, for example roll,thereon. In one example, the running surface is a continuous runningsurface, having no, or substantially free from, discontinuities therein,for example no protrusions (i.e. convexities) thereon or depressions(i.e. concavities) therein. As described above, discontinuities mayincrease loading and/or vibration and hence wear and/or fatigue.

In one example a discontinuity in the running surface, measured normaland/or parallel thereto, between the first rail section and the secondrail section is at most 1 mm, preferably at most 0.5 mm.

In one example, the running surface comprises a planar running surfaceand/or a non-planar running surface, for example a concave runningsurface or a convex running surface.

The rail coupling comprises the first part and the second part. Itshould be understood that the first part and the second part areseparable parts i.e. not integrally formed or permanently coupled, forexample.

The rail coupling comprises the first part having the first endcomprising the first male coupling member and the second end arrangedfor joining to the first rail.

It should be understood that the first end of the first part and thesecond end of the first part are respective opposed ends of the firstpart.

It should be understood that the first male coupling member is arrangedto be received in the corresponding first female coupling member. Thatis, the first male coupling member and the corresponding first femalecoupling member are arranged thus by configuration and/or adaption, forexample shaping. In one example, the first male coupling member and thecorresponding first female coupling member have corresponding shapes,for example a plug and a socket respectively.

It should be understood that the second end of the first part issuitable for joining, for example permanently joining such as by weldingor non-permanently such as by adhesion or an interference fit, to thefirst rail, thereby structurally, securely and/or rigidly joining thefirst part and the first rail. It should be understood that suchnon-permanently joining methods may not be releasable and/or may resultin damage during release and/or may preclude rejoining.

In one example, the first male coupling member comprises a protrusion,for example a plug.

In one example, the first male coupling member comprises a circularexternal cross-sectional shape. In one example, the first male couplingmember comprises a cylindrical external shape or a frustoconicalexternal shape. In this way, the first male coupling member may beprovided, for example machined such as turned, to a high toleranceand/or surface finish. In this way, relative transverse movement betweenthe first male coupling member and the first female coupling member isreduced, reducing discontinuities therebetween and/or wear due tomovement, in use. In one example, an external diameter D_(m1,ext) of thefirst male coupling member is provided, for example machined such asturned, to a tolerance within a range from −0.05 mm to +0.00 mm,preferably within a range from −0.02 mm to +0.00 mm, more preferablywithin a range from −0.01 mm to +0.00 mm of a first coupling memberdiameter D.

In one example, a ratio of a length of the first male coupling member toa cross-sectional dimension, for example a diameter or a width, thereof,is in a range from 0.5:1 to 5:1, preferably in a range from 1:1 to 3:1,more preferably in a range from 1.5:1 to 2.5:1. In this way, an amountof the male member received by the female member is relatively large,such that removal therefrom is requires correspondingly relatively largemovement, thereby reducing likelihood of failure, in use, by uncouplingdue to abnormal loading, for example, and/or better resisting largeplastic deformation of the first rail and/or the second withoutcatastrophic failure of the rail coupling and/or the rail.

The rail coupling comprises the second part having the first endcomprising the corresponding first female coupling member, arranged toreceive the first male coupling member therein, and the second endarranged for joining to the second rail.

The second part may be as described with respect to the first part,mutatis mutandis.

It should be understood that the first end of the second part and thesecond end of the second part are respective opposed ends of the secondpart.

It should be understood that the first female coupling member isarranged to receive the corresponding first male coupling member. Thatis, the first male coupling member and the corresponding first femalecoupling member are arranged thus by configuration and/or adaption, forexample shaping. In one example, the first male coupling member and thecorresponding first female coupling member have corresponding shapes,for example a plug and a socket respectively.

It should be understood that the second end of the second part issuitable for joining, for example permanently joining such as by weldingor non-permanently such as by adhesion or an interference fit, to thesecond rail, thereby structurally, securely and/or rigidly joining thesecond part and the second rail. It should be understood that suchnon-permanently joining methods may not be releasable and/or may resultin damage during release and/or may preclude rejoining. In other words,non-permanent joining is not necessarily releasable coupling, asdescribed herein.

In one example, the first female coupling member comprises a concavity,for example a socket.

In one example, the first female coupling member comprises a circularinternal cross-sectional shape i.e. a circular bore. In one example, thefirst female coupling member comprises a cylindrical internal shape or afrustoconical internal shape. In this way, the first female couplingmember may be provided, for example machined such as turned, to a hightolerance and/or surface finish. In this way, relative transversemovement between the first male coupling member and the first femalecoupling member is reduced, reducing discontinuities therebetween and/orwear due to movement, in use. In one example, an internal diameterD_(f1,int) of the first female coupling member is provided, for examplemachined such as turned, bored or drilled, to a tolerance within a rangefrom −0.00 mm to +0.05 mm, preferably within a range from −0.00 mm to+0.02 mm, more preferably within a range from 0.00 mm to +0.01 mm of thefirst coupling member diameter D. In this way, the first male couplingmember is received closely (i.e. close fitting) in the first femalecoupling member, whereby a gap therebetween is as determined by thetolerances. Particularly, a such a machined-to-machined releasablycoupling effectively transfers load therethrough between adjacent rails.

In one example, a ratio of a length of the first female coupling memberto a cross-sectional dimension, for example a diameter or a width,thereof, is in a range from 0.5:1 to 5:1, preferably in a range from 1:1to 3:1, more preferably in a range from 1.5:1 to 2.5:1. In this way, anamount of the male member received by the female member is relativelylarge, such that removal therefrom is requires correspondinglyrelatively large movement, thereby reducing likelihood of failure, inuse, by uncoupling due to abnormal loading, for example, and/or betterresisting large plastic deformation of the first rail and/or the secondwithout catastrophic failure of the rail coupling and/or the rail.

In one example, the first female coupling member is arranged to slidablyreceive, for example axially, the first male coupling member therein. Inthis way, coupling and uncoupling is facilitated.

In one example, the first male coupling member and the first femalecoupling member are arranged to interlock, for example, upon fullyreceiving the first male coupling member in the first female couplingmember. In this way, inadvertent or accidental uncoupling may beprevented.

In one example, the first male coupling member and the first femalecoupling member are correspondingly threaded. In this way, load transferbetween the first part and the second part may be improved.

The rail coupling is arrangeable in the first configuration wherein thefirst male coupling member and the first female coupling member areuncoupled. That is, the first configuration is a disassembledconfiguration, for example, in which the first male coupling member andthe first female coupling member are separate, for example spaced apart,such as by a gap.

The rail coupling is arrangeable in the second configuration wherein thefirst male coupling member and the first female coupling member arecoupled by receiving the first male coupling member in the first femalecoupling member. That is, the second configuration is an assembledconfiguration, for example an in use configuration.

Running Surface

The rail coupling provides a third portion of the running surface in thesecond configuration.

As described above, the first rail provides the first portion of therunning surface for the wheel, for example of a trolley, and the secondrail providing the second portion of the running surface. That is, therunning surface is a surface for the wheel to run, for example roll,thereon. In one example, the running surface is a continuous runningsurface, having no, or substantially free from, discontinuities therein,for example no protrusions (i.e. convexities) thereon or depressions(i.e. concavities) therein. As described above, discontinuities mayincrease loading and/or vibration and hence wear and/or fatigue. In oneexample, the running surface comprises a planar running surface and/or anon-planar running surface, for example a concave running surface or aconvex running surface.

Hence, in the second configuration, the third portion of the runningsurface is thus arranged between the first portion and the secondportion. That is, the wheel runs on respective portions of the runningsurface provided successively by the first rail, the rail coupling andthe second rail. Hence, rather than a single interface being definedconventionally, in use, between a first rail and a second rail, twointerfaces (i.e. between the first rail and the rail coupling andbetween the rail coupling and the second rail) are instead defined, inuse. Thus, discontinuities (particularly steps) otherwise arising at thesingle interface due to relatively poorer tolerancing and/misshaping ofthe first rail and the second rail may be averaged due to relativelytighter tolerancing of the rail coupling, for example, thereby providinga more continuous running surface.

In one example, the first end of the second part provides, at least inpart, the third portion of the running surface. That is, the firstfemale coupling member and the, at least in part, the third portion ofthe running surface are both at the first end. In one example, anexternal surface of the first female coupling member provides, at leastin part, the third portion of the running surface.

In one example, the first part provides, at least in part, the thirdportion of the running surface. In one example, a surface of the firstpart proximal to the second end provides, at least in part, the thirdportion of the running surface. In one example, the second end of thefirst part comprises a second male coupling and a surface of the firstpart between the first end and the second end provides, at least inpart, the third portion of the running surface.

In one example, the first part provides, at least in part, the thirdportion of the running surface and the first end of the second partprovides, at least in part, the third portion of the running surface. Inone example, the first part and the second part provide similar or equalparts of the third portion of the running surface.

In one example, the running surface comprises a cylindrical runningsurface or a part thereof, for example as provided by a tube or a halfround section. In one example, the first rail comprises a first tubehaving an external diameter D_(ext), whereby the first portion of therunning surface comprises a first portion of a cylindrical runningsurface, the second rail comprises a second tube having a diameterD_(ext) (i.e. the same diameter as the first tube, at least nominally),whereby the second portion of the running surface comprises a secondportion of the cylindrical running surface and the rail couplingcomprises a cylindrical region or part thereof having a diameter D_(ext)(i.e. the same diameter as the first tube and the second tube, at leastnominally), whereby the third portion of the running surface comprises athird portion of the cylindrical running surface.

Relief Region

In one example, the first male coupling member and/or the first femalecoupling member comprises a relief region, arranged to facilitate movingthe rail coupling between the first configuration and the secondconfiguration. In this way, moving the rail coupling from the firstconfiguration to the second configuration is facilitated because mutualalignment of the first male coupling member and the first femalecoupling member is relaxed. For example, for a plug and socketcomprising such a relief region, insertion may be initially off axis andguided to coaxial full insertion.

In one example, the first male coupling member comprises a plugcomprising a relief region provided in an intermediate region thereof,for example having a relatively smaller diameter than adjacent regionsthereto. In one example, the first female coupling member comprises asocket comprising a relief region provided in an intermediate regionthereof, for example having a relatively larger diameter than adjacentregions thereto.

Joining to End of Rail

In one example, the second end of the first part is arranged forjoining, for example by welding, to an end of the first rail and/or thesecond end of the second part is arranged for joining to an end of thesecond rail.

In one example, the second end of the first part comprises a second malecoupling and/or a second female coupling member for joining to the firstrail. In one example, the second end of the second part comprises asecond male coupling and/or a second female coupling member for joiningto the first rail.

In one example, the first rail comprises a first tube having an internaldiameter D_(int), the second rail comprises a second tube having aninternal diameter D_(int) (i.e. the same internal diameter as the firsttube, at least nominally), the second end of the first part comprises asecond male coupling having an external diameter D_(m2,ext) whereD_(m2,ext) is compatible with D_(int) and the second end of the secondpart comprises a second male coupling having an external diameterD_(m2,ext) where D_(m2,ext) is compatible with D_(int). It should beunderstood that where D_(m2,ext) is compatible with D_(int) means thatD_(m2,ext) is at most D_(int). In one example, an external diameterD_(m2,ext) of the second male coupling member is provided, for examplemachined such as turned, to a diameter within a range from −2.00 mm to−0.25 mm, preferably within a range from −1.50 mm to −0.50 mm, morepreferably within a range from −1.00 mm to −0.75 mm with respect toD_(int). In this way, insertion of the second male coupling into thefirst rail, for example, is facilitated. In contrast to the relativelyclose fit between the first male coupling and the first female coupling,the relatively looser fit between the second male coupling and the firstrail, for example, is afforded since the first part and the first railare joined permanently such as by welding or non-permanently such as byadhesion, thereby structurally, securely and/or rigidly joining thefirst part and the first rail.

Material

In one example, the rail coupling is formed from steel according to EN10025: part 2: 2004 grade S185, S235, S275, S355 or equivalent. In oneexample, the rail coupling is coated, for example powder coated, paintedand/or galvanized, to improve corrosion resistance.

Third Part

In one example, the rail coupling comprises a third part, for example aset of fishplates including a first fishplate, for attaching to thefirst rail and the second rail. In this way, the first rail and thesecond rail may be mutually aligned. In one example, the first fishplate comprises a set of perforations therethrough for mechanicallyattaching, for example using mechanical fasteners such as dowels and/orthreaded fasteners, to one side of respective flanges of the first railand the second rail via a set of congruent perforations included in therespective flanges at adjacent ends of the first rail and the secondrail. In one example, the set of fishplates includes the first fishplateand a second fishplate, comprising respective set of perforationstherethrough, for mechanically attaching, for example using threadedfasteners, to both sides of respective flanges of the first rail and thesecond rail via a set of congruent perforations included in therespective flanges at adjacent ends of the first rail and the secondrail. In one example, the perforations are closely toleranced, forexample in a range from +0.10 to +0.20 with respect to the mechanicalfasteners, for example a shank thereof. For example, the perforationsmay have a diameter of 14.00 mm for M14 bolts having a shank diameter of13.80 mm or a diameter of 12.00 mm for M12 bolts having a shank diameterof 11.80 mm.

The first male coupling member and the first female coupling member(hence the first part and the second part), arranged in the secondconfiguration, effectively transfer the forces between the first railand the second rail. In contrast, the third part transfers only arelatively small proportion of the forces between the first rail and thesecond rail, such that imposed forces on the mechanical fastenerstherethrough are relatively low.

Rail

In one example, the rail comprises a planar (i.e. a flat) runningsurface, for example provided by a square or rectangular bar or hollowsection and/or by an equal or unequal angle section. In one example, therail comprises a non-planar, for example a convex or a concave runningsurface. In one example, the rail comprises a cylindrical (i.e. aconvex) running surface defining a cylinder axis, wherein the line issubstantially coincident, in use, with the cylinder axis, for exampleprovided by a tube (i.e. a section) having a circular cross-section or apart thereof, such as a U shape channel. Hollow section is preferred,reducing a weight of the rail. In one example, the tube has an externaldiameter D_(ext) in a range from 40 mm to 100 mm, preferably in a rangefrom 50 mm to 75 mm, for example 60.3 mm. In one example, the tube has awall thickness in a range from 1 mm to 6 mm, preferably in a range from2 mm to 5 mm, for example 3 mm or 4 mm, for example 3.2 mm. In oneexample, the tube has an internal diameter D_(int) in a range from 35 mmto 95 mm, preferably in a range from 45 mm to 70 mm.

In one example, the rail comprises a non-linear, for example a curved,portion. In this way, the non-linear portion enables the rail to curvearound obstacles, for example, and/or to increase user enjoyment, asdescribed above. It should be understood that the non-linear portion isgenerally sideways (i.e. transverse to a general direction of travel ofa trolley), though the rail may curve sideways and up or down also.

In one example, the rail comprises two or more rails, for example twoparallel rails. In one example, the rail is a monorail (i.e. a singlerail). A monorail is preferred, reducing cost and/or weight, may befixed readily to a framework or hung from ceiling joists or trees, forexample, and/or may be formed into relatively complex shapes, includingmultiple non-linear and linear portions that may also ascend, descendand/or be horizontal.

In one example, the rail is formed from steel according to EN 10025:part 2: 2004 grade S185, S235, S275, S355 or equivalent. In one example,the tube is seamless tube. In one example, the rail is coated, forexample powder coated, painted and/or galvanized, to improve corrosionresistance.

In one example, the rail comprises a flange. The flange (also known as aweb or a stiffener) increases a stiffness of the rail, for example aresistance to bending of the rail.

In one example, the rail comprises a cylindrical tube, wherein therunning surface comprises a cylindrical running surface or a partthereof and wherein the rail comprises a flange.

In this way, relatively complex non-linear paths may be provided,including lateral deviations, such as curves or bends, and/or one ormore descending portions, ascending portions and/or horizontal portions,for example by forming, such as bending or rolling the tube.Furthermore, since the tube has cylindrical symmetry, a transversecurvature of the running surface is relatively invariant, including forrelatively complex non-linear paths, thereby providing a more continuousrunning surface.

In one example, the flange is arranged upstanding from the tube i.e.extending away therefrom. In one example, the flange is arrangedlongitudinally with respect to the tube. In one example, the flange isoriented normally to the running surface. In one example, the railcomprises a longitudinal flange. In one example, the flange is arrangedto provide a fixing means, for example a lifting eye or a perforation ora set thereof through the flange, for suspension of the rail therefrom.Other fixing means are known. In this way, the rail may be fixed to, forexample suspended from, a framework or hung from ceiling joists ortrees, for example, such that a region under the rail remainsunobstructed for the trolley and the user to travel through. In oneexample, the longitudinal flange comprises a first set of perforationsfor suspension. In one example, the longitudinal flange comprises asecond set of perforations, congruent with a set of perforationsprovided in a third part of the rail coupling. In one example, thelongitudinal flange extends continuously along a length of the rail. Inone example, the flange is welded to the tube, for example continuouslyor intermittently (i.e. stitch welding, for example on alternate sidesof the flange).

In one preferred example, the rail comprises a cylindrical tube, whereinthe running surface comprises a cylindrical running surface or a partthereof and wherein the rail comprises a longitudinal flange normal tothe tube (i.e. upstanding therefrom) extending continuously along thetube.

In one example, a length of the flange is greater than a length of thetube. For example, the flange may extend beyond one or both ends of thetube. In one example, the flange extends beyond both ends of the tube,by distances correlating or coinciding (i.e. equal to or substantiallyequal to) respective lengths, or parts thereof, of the third portion ofthe running surface provided by the first part and/or the second part ofthe rail coupling joined thereto. In this way, the respective ends offlanges of adjacent rails abut or confront when the rail coupling isarranged in the second configuration.

Rail Section

A second aspect provides a rail section providing a portion of a runningsurface for a wheel, the rail section comprising a rail and a first partand/or a second part of a rail coupling, according to the first aspect,joined thereto.

The running surface and/or the rail may be as described with respect tothe first aspect. For example, the rail may be as described with respectto the first rail or the second rail of the first aspect.

In one example, the rail comprises a cylindrical tube, wherein therunning surface comprises a cylindrical running surface or a partthereof and wherein the rail comprises a flange.

In this way, relatively complex non-linear paths may be provided,including lateral deviations, such as curves or bends, and/or one ormore descending portions, ascending portions and/or horizontal portions,for example by forming, such as bending or rolling the tube.Furthermore, since the tube has cylindrical symmetry, a transversecurvature of the running surface is relatively invariant, including forrelatively complex non-linear paths, thereby providing a more continuousrunning surface.

In one example, the rail is provided in lengths that are coupled end toend, for example on site.

Method of Manufacturing

A third aspect provides a method of manufacturing a rail sectionaccording to the second aspect, the method comprising:

joining, by welding, the first part and/or the second part of the railcoupling member to the rail;

and

optionally, machining the weld.

In one example, the method comprises providing the rail by joining, bywelding for example stitch welding, a flange to a tube, therebyproviding the rail. In one example, the method comprises forming, forexample by bending and/or rolling, the tube/or and the flange, therebyforming a curve therein, preferably before joining the flange to thetube. In one example, a length of the flange is greater than a length ofthe tube and the method comprises arranging the flange to extend beyondone or both ends of the tube, before joining the flange to the tube. Inone example, the method comprises arranging the first part and/or thesecond part whereby respective lengths, or parts thereof, of the thirdportion of the running surface provided by the first part and/or thesecond part of the rail coupling correlate or coincide (i.e. equal to orsubstantially equal to) respective lengths, or parts thereof, of theflange extending beyond one or both ends of the tube. In this way, therespective ends of flanges of adjacent rails abut or confront when therail coupling is arranged in the second configuration.

Rail Assembly or Kit of Parts Thereof

A fourth aspect provides a rail assembly (also known as a rail track),or a kit of parts for a rail assembly, comprising a set of railsections, including a first rail section and a second rail section,according to the second aspect.

In one example, the rail assembly comprises a set of M rail sections,wherein M is a natural number greater than 2, 5, 10, 20, 30, 40, 50,100, or more. In this way, a rail track may be conveniently provided. Inone example, each rail section has a length in a range from 1 m to 40 m,preferably in a range from 2 m to 30 m, more preferably in a range from5 m to 20 m, for example 9 m, 10 m, or 12 m.

Method of Assembling

A fifth aspect provides a method of assembling a rail assembly accordingto the fourth aspect, comprising:

moving the rail coupling from the first configuration to the secondconfiguration.

In one example, the method comprises disassembling the rail assembly bymoving the rail coupling from the second configuration to the firstconfiguration.

Trolley

According to an aspect, there is provided a trolley for a rail, thetrolley comprising:

a frame;

a set of wheels, including a first wheel and a second wheel, rotatablycoupled to the frame;

and

an attachment member, coupled to the frame, for attachment, preferablysuspension, of a load therefrom, in use;

wherein the first wheel is rotatable in a first plane about a first axisand the second wheel is rotatable in a second plane about a second axis;

wherein the first plane and the second plane define a line;

wherein the trolley is arrangeable in:

a first configuration, wherein the attachment member is arranged at afirst angular displacement about the line; and

a second configuration, wherein the attachment member is arranged at asecond angular displacement about the line, wherein the first angulardisplacement and the second angular displacement are different.

Definitions

Throughout this specification, the term “comprising” or “comprises”means including the component(s), unit(s), module(s), feature(s) orinteger(s) specified but not to the exclusion of the presence of othercomponents, units, modules, features or integers.

The term “consisting of” or “consists of” means including thecomponent(s), unit(s), module(s), feature(s) or integer(s) specified butexcluding other components, units, modules, features or integers.

Whenever appropriate, depending upon the context, the use of the term“comprises” or “comprising” may also be taken to include the meaning“consists essentially of” or “consisting essentially of”, and also mayalso be taken to include the meaning “consists of” or “consisting of”.

The optional features set out herein may be used either individually orin combination with each other where appropriate and particularly in thecombinations as set out in the accompanying claims. The optionalfeatures for each aspect or exemplary embodiment of the invention, asset out herein are also applicable to all other aspects or exemplaryembodiments of the invention, where appropriate. In other words, theskilled person reading this specification should consider the optionalfeatures for each aspect or exemplary embodiment of the invention asinterchangeable and combinable between different aspects and exemplaryembodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention, and to show how exemplaryembodiments of the same may be brought into effect, reference will bemade, by way of example only, to the accompanying diagrammatic Figures,in which:

FIG. 1 schematically depicts an exploded plan view of a rail assemblyaccording to an exemplary embodiment, including a rail couplingaccording to an exemplary embodiment arranged in a first configuration;

FIG. 2 schematically depicts plan view of the rail assembly of FIG. 1,including the rail coupling arranged in a second configuration;

FIG. 3 schematically depicts a longitudinal cross-sectional view of therail coupling of FIG. 2;

FIG. 4 schematically depicts a longitudinal cross-sectional view of therail coupling of FIG. 3, in more detail;

FIG. 5 schematically depicts a perspective view of a first part of therail coupling of FIG. 1;

FIG. 6 schematically depicts a perspective view of a second part of therail coupling of FIG. 1;

FIG. 7 schematically depicts (A) a front elevation view; (B) a sideelevation view; and (C) an rear elevation view of the first part of therail coupling of FIG. 5;

FIG. 8 schematically depicts (A) a front elevation view; (B) a sideelevation view; (C) an rear elevation view; and (D) a longitudinalcross-sectional view of the second part of the rail coupling of FIG. 6;

FIG. 9 schematically depicts (A) a plan view; (B) a side elevation view;and (C) a front elevation view of a rail of the rail assembly of FIG. 1;

FIG. 10 schematically depicts (A) a perspective view; (B) a sideelevation view; and (C) a front elevation view of a third part of therail assembly of FIG. 1; and

FIG. 11 schematically depicts a perspective view of the rail assembly ofFIG. 1, including a trolley thereon.

DETAILED DESCRIPTION OF THE DRAWINGS

Rail Coupling

FIG. 1 schematically depicts an exploded plan view of a rail assembly 1according to an exemplary embodiment, including a rail coupling 1000according to an exemplary embodiment arranged in a first configuration.

FIG. 2 schematically depicts plan view of the rail assembly 1 of FIG. 1,including the rail coupling 1000 arranged in a second configuration.

FIG. 3 schematically depicts a longitudinal cross-sectional view of therail coupling 1000 of FIG. 2.

FIG. 4 schematically depicts a longitudinal cross-sectional view of therail coupling 1000 of FIG. 3, in more detail.

The releasable rail coupling 1000 is for releasably coupling a firstrail 10A providing a first portion P1 of a running surface RS for awheel 120 and a second rail 10B providing a second portion P2 of therunning surface RS. The rail coupling 1000 comprises a first part 1100having a first end 1110 comprising a first male coupling member 1111 anda second end 1120 arranged for joining to the first rail 10A. The railcoupling 1000 comprises a second part 1200 having a first end 1210comprising a corresponding first female coupling member 1212, arrangedto receive the first male coupling member 1111 therein, and a second end1220 arranged for joining to the second rail 10B. The rail coupling 1000is arrangeable in a first configuration wherein the first male couplingmember 1111 and the first female coupling member 1212 are uncoupled. Therail coupling 1000 is arrangeable a second configuration wherein thefirst male coupling member 1111 and the first female coupling member1212 are coupled by receiving the first male coupling member 1111 in thefirst female coupling member 1212. The rail coupling 1000 provides athird portion P3 of the running surface RS in the second configuration.

In this way, assembly and/or disassembly of the first rail 10A (i.e. afirst length of rail) and the second rail 10B (i.e. a second length ofrail) may be facilitated and/or errors in assembly reduced.

FIG. 5 schematically depicts a perspective view of the first part 1100of the rail coupling 1000 of FIG. 1.

FIG. 6 schematically depicts a perspective view of the second part 1200of the rail coupling 1000 of FIG. 1.

FIG. 7 schematically depicts (A) a front elevation view; (B) a sideelevation view; and (C) an rear elevation view of the first part 1100 ofthe rail coupling 1000 of FIG. 5.

FIG. 8 schematically depicts (A) a front elevation view; (B) a sideelevation view; (C) an rear elevation view; and (D) a longitudinalcross-sectional view of the second part 1200 of the rail coupling 1000of FIG. 6.

In this example, the first male coupling member 1111 and thecorresponding first female coupling member 1212 have correspondingshapes, particularly a plug and a socket respectively.

In this example, the first male coupling member 1111 comprises acylindrical external shape i.e. a plug. In this example, an externaldiameter D_(m1,ext) of the first male coupling member 1111 is turned toa tolerance within a range from −0.02 mm to +0.00 mm of a first couplingmember diameter D of 51.00 mm.

In this example, a ratio of a length L_(m1) of the first male couplingmember 1111 to the external diameter D_(m1,ext) thereof is about 2.4:1.

The second part 1200 is as described with respect to the first part1100, mutatis mutandis.

In this example, the first female coupling member 1212 comprises acylindrical internal shape. In this example, an internal diameterD_(f1,int) of the first female coupling member 1212 is bored to atolerance within a range from −0.00 mm to +0.02 mm of the first couplingmember diameter D of 51.00 mm.

In this example, a ratio of a length L_(f1) of the first female couplingmember 1212 to the internal diameter D_(f1,int) thereof is about 2.5:1.

In this example, the first female coupling member 1212 is arranged toslidably receive, axially, the first male coupling member 1111 therein.

Running Surface

In this example, the running surface RS is a continuous running surfaceRS, having no, or substantially free from, discontinuities therein, forexample no protrusions (i.e. convexities) thereon or depressions (i.e.concavities) therein. In this example, the running surface RS comprisesa convex, particularly a cylindrical, running surface RS.

In this example, the first part 1100 provides, at least in part, thethird portion P3 of the running surface RS and the first end 1110 of thesecond part 1200 provides, at least in part, the third portion P3 of therunning surface RS. In this example, the first part 1100 and the secondpart 1200 provide similar or equal parts of the third portion P3 of therunning surface RS. In this example, an external surface of the firstfemale coupling member 1212 provides, at least in part, the thirdportion P3 of the running surface RS.

In this example, the running surface RS comprises a cylindrical runningsurface RS or a part thereof, for example as provided by a tube 11. Inthis example, the first rail 10A comprises a first tube 11 having anexternal diameter D_(ext) of 60.3 mm, whereby the first portion P1 ofthe running surface RS comprises a first portion P1 of a cylindricalrunning surface RS, the second rail 10B comprises a second tube 11having a diameter D_(ext) (i.e. the same diameter as the first tube 11,at least nominally), whereby the second portion P2 of the runningsurface RS comprises a second portion P2 of the cylindrical runningsurface RS and the rail coupling 1000 comprises a cylindrical region orpart thereof having a diameter D_(ext) (i.e. the same diameter as thefirst tube 11 and the second tube 11, at least nominally), whereby thethird portion P3 of the running surface RS comprises a third portion P3of the cylindrical running surface RS.

Relief Region

In this example, the first female coupling member 1212 comprises asocket comprising a relief region 1213 provided in an intermediateregion thereof, having a relatively larger diameter than adjacentregions thereto. In this example, an internal diameter D_(f1,rr) of therelief region 1213 of the first female coupling member 1212 is bored towithin a range from +2.00 mm to +2.50 mm of the internal diameterD_(f1,int).

Joining to End of Rail

In this example, the second end 1120 of the first part 1100 comprises asecond male coupling 1121 for joining to the first rail 10A. In thisexample, the second end 1220 of the second part 1200 comprises a secondmale coupling 1221 for joining to the second rail 10B.

In this example, the first rail 10A comprises a first tube 11A having aninternal diameter D_(int) of 53.9 mm the second rail 10B comprises asecond tube 11B having an internal diameter D_(int) (i.e. the sameinternal diameter as the first tube 11A, at least nominally), the secondend 1120 of the first part 1100 comprises a second male coupling 1121having an external diameter D_(m2,ext) where D_(m2,ext) is compatiblewith D_(int) and the second end 1120 of the second part 1200 comprises asecond male coupling 1221 having an external diameter D_(m2,ext) whereD_(m2,ext) is compatible with D_(int). It should be understood thatwhere D_(m2,ext) is compatible with D_(int) means that D_(m2,ext) is atmost D_(int). In this example, an external diameter D_(m2,ext) of thesecond male coupling member 1121 is turned to within a range from −1.00mm to −0.75 mm with respect to D_(int). In this way, insertion of thesecond male coupling 1121 into the first rail 10A, for example, isfacilitated.

Material

In this example, the rail coupling 1000 is formed from steel accordingto EN 10025: part 2: 2004 grade S355. In this example, the rail coupling1000 is powder coated.

Third Part

FIG. 10 schematically depicts (A) a perspective view; (B) a sideelevation view; and (C) a front elevation view of a third part 1300 ofthe rail assembly 1 of FIG. 1.

In this example, the rail coupling 1000 comprises a third part 1300,particularly a set of fishplates, for attaching to the first rail 10Aand the second rail 10B, particularly to respective flanges thereof. Inthis way, the first rail 10A and the second rail 10B may be mutuallyaligned. In this example, the first fish plate 1300 comprises a set ofperforations 1303 therethrough for mechanically attaching, for exampleusing mechanical fasteners such as dowels and/or threaded fasteners, toone side of respective flanges 12A, 12B of the first rail 10A and thesecond rail 10B via the set of congruent perforations 13 included in therespective flanges 12A, 12B at adjacent ends of the first rail and thesecond rail. In this example, the set of fishplates includes the firstfishplate and a second fishplate, comprising respective set ofperforations therethrough, for mechanically attaching, for example usingthreaded fasteners, to both sides of respective flanges of the firstrail and the second rail via a set of congruent perforations included inthe respective flanges at adjacent ends of the first rail and the secondrail. In this example, the perforations are closely toleranced, forexample in a range from +0.10 to +0.20 with respect to the mechanicalfasteners, for example a shank thereof. For example, the perforationsmay have a diameter of 14.00 mm for M14 bolts having a shank diameter of13.80 mm or a diameter of 12.00 mm for M12 bolts having a shank diameterof 11.80 mm.

Rail

FIG. 9 schematically depicts (A) a plan view; (B) a side elevation view;and (C) a front elevation view of the rail 10 of the rail assembly 1 ofFIG. 1.

In this example, the rail 10 (i.e. the first rail 10A and/or the secondrail 10B) comprises a cylindrical (i.e. a convex) running surface RS. Inthis example, the rail comprises a cylindrical tube 11, wherein therunning surface RS comprises a cylindrical running surface RS or a partthereof and wherein the rail comprises a flange 12. In this example, thetube 11 has an external diameter D_(ext) of 60.3 mm. In this example,the tube 11 has a wall thickness of 3.2 mm. In this example, the tube 11has an internal diameter D_(int) of 53.9 mm.

In this example, the rail 10 is a monorail (i.e. a single rail).

In this example, the rail 10 is formed from steel according to EN 10025:part 2: 2004 grade S275 or equivalent. In this example, the tube 11 isseamless tube 11. In this example, the rail 10 is powder coated.

In this example, the flange 12, having a thickness of 12 mm and a heightof 100 mm, is arranged upstanding from the tube 11 i.e. extending awaytherefrom. In this example, the flange 12 is arranged longitudinallywith respect to the tube 11. In this example, the flange 12 is orientednormally to the running surface RS. In this example, the rail comprisesa longitudinal flange 12. In this example, the flange 12 is arranged toprovide a fixing means, particularly a first set of four perforations 13through the flange 12. In this example, the longitudinal flange 12comprises a second set of four perforations through the flange 12. Inthis example, the longitudinal flange 12 extends continuously along alength of the rail. In this example, the flange 12 is welded to the tube11, for example continuously or intermittently (i.e. stitch welding, forexample on alternate sides of the flange 12).

In this example, a length of the flange 12 is greater than a length ofthe tube 11. In this example, the flange 12 extends beyond both ends ofthe tube 11, by distances correlating or coinciding (i.e. equal to orsubstantially equal to) respective lengths, or parts thereof, of thethird portion P3 of the running surface RS provided by the first part1100 and/or the second part 1200 of the rail coupling 1000 joinedthereto.

Trolley

FIG. 11 schematically depicts a perspective view of the rail assembly 1of FIG. 1, including a trolley 100 thereon.

In this example, the trolley 100 comprises a frame 110; a set of wheels120, including the first wheel 110A and a second wheel 120B, rotatablycoupled to the frame 110; and an attachment member (not shown), coupledto the frame 110, for attachment, preferably suspension, of the load Ltherefrom, in use. The first wheel 110A is rotatable in a first planeabout a first axis and the second wheel is rotatable in a second planeabout a second axis. The first plane and the second plane define a line.The trolley 100 is arrangeable in: a first configuration, wherein theattachment member (not shown) is arranged at a first angulardisplacement about the line; and

a second configuration, wherein the attachment member (not shown) isarranged at a second angular displacement about the line, wherein thefirst angular displacement and the second angular displacement aredifferent.

In this example, the trolley 100 is a captive trolley 100, as describedabove. In this example, the set of wheels 120 are arranged to retain thetrolley 100 on a rail.

Although a preferred embodiment has been shown and described, it will beappreciated by those skilled in the art that various changes andmodifications might be made without departing from the scope of theinvention, as defined in the appended claims and as described above.

In summary, a releasable rail coupling, a rail section comprising a partof a rail coupling, a method of manufacturing a rail section, a railassembly and a kit of parts for a rail assembly including a set of railsections and a method of assembling a rail assembly are provided.

The releasable rail coupling is for releasably coupling a first railproviding a first portion of a running surface for a wheel and a secondrail providing a second portion of the running surface, the railcoupling comprising: a first part having a first end comprising a firstmale coupling member and a second end arranged for joining to the firstrail; and a second part having a first end comprising a correspondingfirst female coupling member, arranged to receive the first malecoupling member therein, and a second end arranged for joining to thesecond rail; wherein the rail coupling is arrangeable in: a firstconfiguration wherein the first male coupling member and the firstfemale coupling member are uncoupled; and a second configuration whereinthe first male coupling member and the first female coupling member arecoupled by receiving the first male coupling member in the first femalecoupling member; wherein the rail coupling provides a third portion ofthe running surface in the second configuration.

In this way, assembly and/or disassembly of the first rail (i.e. a firstlength of rail) and the second rail (i.e. a second length of rail) maybe facilitated and/or errors in assembly reduced.

Attention is directed to all papers and documents which are filedconcurrently with or previous to this specification in connection withthis application and which are open to public inspection with thisspecification, and the contents of all such papers and documents areincorporated herein by reference.

All of the features disclosed in this specification (including anyaccompanying claims and drawings), and/or all of the steps of any methodor process so disclosed, may be combined in any combination, exceptcombinations where at least some of such features and/or steps aremutually exclusive.

Each feature disclosed in this specification (including any accompanyingclaims, and drawings) may be replaced by alternative features servingthe same, equivalent or similar purpose, unless expressly statedotherwise. Thus, unless expressly stated otherwise, each featuredisclosed is one example only of a generic series of equivalent orsimilar features.

The invention is not restricted to the details of the foregoingembodiment(s). The invention extends to any novel one, or any novelcombination, of the features disclosed in this specification (includingany accompanying claims and drawings), or to any novel one, or any novelcombination, of the steps of any method or process so disclosed.

1. A releasable rail coupling for releasably coupling a first railproviding a first portion of a running surface for a wheel and a secondrail providing a second portion of the running surface, the railcoupling comprising: a first part having a first end comprising a firstmale coupling member and a second end arranged for joining to the firstrail; and a second part having a first end comprising a correspondingfirst female coupling member, arranged to receive the first malecoupling member therein, and a second end arranged for joining to thesecond rail; wherein the rail coupling is arrangeable in: a firstconfiguration wherein the first male coupling member and the firstfemale coupling member are uncoupled; and a second configuration whereinthe first male coupling member and the first female coupling member arecoupled by receiving the first male coupling member in the first femalecoupling member; wherein the rail coupling provides a third portion ofthe running surface in the second configuration.
 2. The rail couplingaccording to claim 1, wherein the first female coupling member isarranged to slidably receive, for example axially, the first malecoupling member therein.
 3. The rail coupling according to claim 1,wherein the first male coupling member and/or the first female couplingmember comprises a relief region, arranged to facilitate moving the railcoupling between the first configuration and the second configuration.4. The rail coupling according to claim 1, wherein the second end of thefirst part is arranged for joining to an end of the first rail and/orthe second end of the second part is arranged for joining to an end ofthe second rail.
 5. The rail coupling according to claim 1, wherein thesecond end of the first part comprises a second male coupling and/or asecond female coupling member for joining to the first rail.
 6. The railcoupling according to claim 1, wherein the first male coupling membercomprises a circular cross-sectional shape,
 7. The rail couplingaccording to claim 1, wherein a ratio of a length of the first malecoupling member to a cross-sectional dimension, for example a diameteror a width, thereof, is in a range from 0.5:1 to 5:1, preferably in arange from 1:1 to 4:1, more preferably in a range from 1.5:1 to 3:1. 8.The rail coupling according to claim 1, wherein the first end of thesecond part provides, at least in part, the third portion of the runningsurface.
 9. The rail coupling according to claim 1, wherein the firstpart provides, at least in part, the third portion of the runningsurface.
 10. The rail coupling according to claim 1, wherein the runningsurface comprises a cylindrical running surface or a part thereof. 11.The rail coupling according to claim 1, comprising a third part, forexample a fishplate, for attaching to the first rail and the secondrail.
 12. A rail section providing a portion of a running surface for awheel, the rail section comprising a rail and a first part and/or asecond part of a rail coupling, according to claim 1, joined thereto.13. The rail section according to claim 12, wherein the rail comprises acylindrical tube, wherein the running surface comprises a cylindricalrunning surface or a part thereof and wherein the rail comprises aflange.
 14. A method of manufacturing a rail section according to claim12, the method comprising: joining, by welding, the first part and/orthe second part of the rail coupling member to the rail.
 15. A railassembly, or a kit of parts for a rail assembly, comprising a set ofrail sections, including a first rail section and a second rail section,according to claim
 12. 16. The rail assembly according to claim 15,wherein a discontinuity in the running surface, measured normal and/orparallel thereto, between the first rail section and the second railsection is at most 1 mm.
 17. A method of assembling a rail assemblyaccording to claim 15, comprising: moving the rail coupling from thefirst configuration to the second configuration.
 18. The method of claim14, further comprising: machining the weld.
 19. The rail assembly ofclaim 15, wherein the discontinuity is at most 0.5 mm.